Summary

Researchers have identified what may be a master gene for bone growth. Evidence from human families, knockout mice, and cell culture shows that the gene turns precursor cells into osteoblasts, the cells that secrete bony matrix, and switches on at least one bone protein and probably many more. When mutated, it also causes a disease known as cleidocranial dysplasia, marked by skeletal abnormalities including a missing collarbone, soft spots in the skull, and stunted growth.